6-fluoro steroids and process



' skin 01 mucous membranes.

'6-FLUOR0 STEROIDS AND PROCESS George B. Spero, Kalamazoo Township,Kalamazoo County, Barney J. Magerlein, Kalamazoo, and William P.Schneider and John A. Hogg, Kalamazoo Township, Kalamazoo County, Mich.,assignors to The Upjohn Company, Kalamazoo, Mich., a corporation ofMichigan No Drawing. Application November 29, 1957 Serial No; 699,528

8 Claims. (Cl. 260-397.45)

This invention relates to novel steroids,6-fluorol1fl,l7a-dihydroxy-1,4-pregnadiene-3,20-diones and 6fluoro-17u-hydroxy-1,4-pregnadiene-3,l1,20-triones, and to intermediatesand processes for making the same. It relates particularly to6a-fluoro-1lfi,l7a-dihydroxy-l,4- pregnadiene-3,20-dione(1-dehydro-2l-desoxy-fia-fiuorohydrocortisone) and6m-fluoro-l7a-hydroxy-1,4-pregnadiene 3,11,204rinel-dehydro-Zl-desoxy-6-a-fluorocortisome), intermediates in theproduction thereof and processes for their production.

The novel 1-dehydro-21-desoxy-6-fluorohydrocortisones andl-dehydro-21-desoxy-fi-fluorocortisones possess a high order ofglucocorticoid and anti-inflammatory activity. They are useful in thetreatment of various arthritic conditions and in the control ofinflammatory conditions due to bacterial infections or allergicreactions of The compounds cause a loss of salt and water which makesthem especially valuable in the management of chronic congestive heartfailure and in the treatment of cirrhosis of the liver, the nephroticsyndrome and the treatment of eclampsia and pre-eclampsia. For example,l-dehydro-21-desoxy-6afluorohydrocortisone has glucocorticoid activityof about seven times that of Kendalls compound F and anti-inflammatoryactivity of about eight times that of Kendalls compound F.

The new compounds and the process of the present invention areillustratively represented by the following flow sheet and formulae:

v CHaOH CHaOSQsR United States Patent O I 2,838,542 Patented June 10,

III

CHI

wherein R is an organic radical, particularly a hydrocarbon radical ofup to and including ten carbon atoms, such as ethyl, phenyl, tolyl,naphthyl, or the like, with methyl preferred.

The process of the present invention comprises treating6-fluoro-11,8,17a,2l-trihydroxy-1,4-pregnadiene-3,20- dione (A-6-fluorohydrocortisone) (I) with an organic sulfonyl halide to obtainthe corresponding 2l-ester (II), a 2l-alkyl or 21-arylsulfonate of6-fiuoro-1l 8,17a,21-tri hydroxy-1,4-pregnadiene-3,ZO-dione. Treatingthe thusproduced 21-alkyl or arylsulfonate of 6-fluoro-1lp,17a,21-trihydroxy-l,4-pregnadiene-3,20-dione (II) with an iodinating agentyields G-fiuoro-l1p,17a-dihydroxy-21-iodo- 1,4-pregnadiene-3,20-dione(III). Treating the thus-obtained6-fluoro-2l-iodo-l1B,l7a-dihydroxy-1,4-pregnadiene-3,20-dione (III) witha reducing agent 'to dehalogenate at the 2l-position yields6-fluoro-1118,l7a-dihydroxy-1,4-pregnadiene-3,ZO-dione (IV), which onoxidation gives 6-fluoro-l7a-hydroxy-l,4-pregnadiene-3,11,20- trione(V). a

Similarly, when the ll-keto analogue (1-dehydro-6- fluorocortisone) isutilized as starting material in the above series of reactions,6-fluoro-l7p-hydroxy-l,4-pregr nadiene-3,l1,20-trione (V) is produceddirectly without the step of oxidation of the llp-hydroxyl;

Administration of the novel steroids can 'be in conventional dosageforms, such as pills, tablets, capsules, syrups or elixirs for oral use,or in liquid forms which are adaptable to the natural and syntheticcortical steroid hormones for injectable products. The novel compoundscan also be administered topically in the form of ointments, creams,lotions and the like, with or without coacting antibiotics, germicidesor other materials forming advantageous combinations therewith.

As will hereinafter be described in greater detail, these compounds areadditionally useful as intermediates in the production of6,9a-difluoro-11,8,17a-dihydroxy-1,4-pregnadiene-3,20-dione and6,9a-difluoro-17a-hydroxy-l,4- pregnadiene-3,11,20-trione. The 9tx-haloderivatives are of particular importance because they possess acombination of high anti-inflammatory and glucocorticoid properties withlow concomitant mineralocorticoid activities.

The starting steroids for the compounds and process of the presentinvention are 6a-fluorohydrocortisone or 6B- fluorohydrocortisone or thecorresponding ll-keto analogues and are prepared in accordance with theprocedures of Preparations 1 through 11 herein.

In carrying out the process of this invention, o-fluorohydrocortisone of6-fiuorocortisone is treated with an organic acid sulfonyl halide suchas methanesulfonyl chloride, toluenesulfonyl chloride, toluenesulfonylbromide, benzenesulfonyl chloride, naphthylsulfonyl chloride, or thelike, the methanesulfonic acid halides, especially methanesulfonylchloride, being preferred. In the preferred embodiment, the startingsteroid is reacted with the alkyl or aryl sulfonyl halide in a solventsuch as pyridine, benzene, toluene, or the like. Sufiicient amine base,e. g., pyridine, should be added to react with any halogen acid formed.The sulfonyl halide reaction is conducted at a temperature between minusten and plus sixty degrees centigrade, providing at the lowertemperature the solvent has not solidified. Thus, for pyridine, dioxane,toluene, or the like, temperatures in the range of zero to ten degreescentigrade can be used, while for benzene only temperatures above fivedegrees centigrade are suitable because of the relatively high meltingpoint of the latter compound. The reaction time is usually between aboutthirty minutes and eight hours, after which the product, 6-fluoro-l113,17a,21t1ihydroxy-1,4-pregnadiene-3,20-dione Zl-alkyl orarylsulfonate, is recovered in a conventional manner, such as, forexample, by evapcrating the solvent until a dry residue is obtained,followed, if desired, by mixing the product with Water and extractingthe purified material therefrom. For extraction, solvents such asmethylene chloride, chloroform, carbon tetrachloride, benzene, ether,toluene, or'the like can be used. Removal 'of the extraction solvent bydistillation leaves the crude 21-alkyl or arylsulfonate.

The 21-iodo compound (III) is prepared by reacting the said 2l-alkyl orarylsulfonate with sodium, potassium or lithium iodide in an oxygenatedhydrocarbon solution, e. g., an alkanone solution, such as acetone. Amolar excess of sodium iodide (three to twenty moles of sodium iodideper mole of steroid) is generally preferred for this reaction. Thereaction mixture containing the 21-alkylor arylsulfonate andsodiumiodide and acetone is heated to reflux for a period of about threeminutes to thirty minutes. The thus-produced 6-fiuoro-1l,8,17a-dihydroxy2l-iodo-1,4-pregnadiene-3,20-dione can then be isolated by evaporatingthe solvent. For the subsequent reaction, the 21-iodo steroid can beused either in purified form as a product of recrystallization from suchorganic solvents as acetone, ethanol, Skellysolve B (brand of hexanehydrocarbons), or the like or it can be used in the crude state in thenext step of the synthesis.

The 6-fiuoro-21-iodo-1 13,1711 dihydroxy 1,4 pregnadiene-3,20-dione isthen reacted with a reducing agent such as sodium or potassiumthiosulfate, bisulfite or sulfite, or zinc and acetic acid, or the like.In the preferred embodiment of the invention, the crude 21-iodide isslurried with 'zincand acetic acidand the'mixture stirred at roomtemperature for a period of five minutes to two hours. The product isisolated from the reaction mixture after dilution with water byconventional methods, such as by filtration or extraction with awater-immiscible organic solvent, e. g., ether, benzene, methylenechloride, ethylene chloride, carbontetrachloride, chloroform, hexane,heptane, or the like, and evaporating the solvent. Purification of thethus-obtained 6-fluoro-11B,17a-dihyclroxy-1,4-pregnadiene-3,20-dione iscarried out in the usual manner, such as by recrystallization fromether, acetone, methanol, ethanol, Skellysolve B hexanes or the like, orby chromatography. H

The oxidation of 6-fiuoro-1lB,l7a-dihydroxy-l,4-pregnadiene-3,20-dionecan be carried out by a variety of methods, such as, for example, byoxidizing the said 6- finoro-21-desoxy steroid in acetic acid solutionwith chromium trioxide, using molar quantities or a slight excess, oremploying a haloamide or haloimide of an acid such as N-bromoacetamide,N-chlorosuccinimidc, or N- bromosuccinimide in pyridine, dioxane, orother solvent solutions. After conclusion of the desired oxidation, theoxidant is generally destroyed by addition of methyl alcohol, ethylalcohol, or the like when chromic acid is the oxidizing agent, and analkali bisulfite when N-bromosuccinirnide or other N-haloacylamides areused. Thereafter 6-fiuoro-l7a-hydroxy-l,4-pregnadiene-3,l 1,20-trione(V) is obtained by conventional means, such as extraction withwater-immiscible solvents, e. g., methylene chloride, ethylene chloride,chloroform, carbon tetrachloride, ether, benzene, toluene, or the like,and is purified by recrystallization or by chromatography.

As hereinbefore indicated, the compounds of the presour invention areadditionally useful as intermediates in the production of the valuable9a-fiu0ro derivatives by a 9a-halogenation procedure. Thus,6-fluoro-l1/3,17adihydroxy-1,4-pregnadiene-3,ZO-dione can be dehydratedwith N-bromoacetamide and anhydrous sulfur dioxide in pyridine solutionby permitting the reaction to continue until a negative acidifiedpotassium iodide-starch test of the reaction mixture is obtained.Dilution with cold water results in the precipitation of6-fiuoro-l7a-hydroxyl,4,9(ll)-pregnatriene-3,20-dione, which can bepurified by recrystallization from acetone. The crystalline product canthen be reacted in methylene chloride-tertiary butyl alcohol solutionwith perchloric acid and N-bronioacetamide or N-iodosuccinimide toproduce a reaction mixture from which 6-fiuoro-9u-bromo-ll,8,l7z-dihyciroxy-1,4-pregnadiene-3,20-dione or the corresponding 6-fluoro-9u-iodo compound can be recovered by precipitation with ice waterand recrystallization from acetone. The latter steroids can then bereacted in acetone solution with anhydrous potassium acetate at refluxtemperatures to produce 6-fluoro-9 l1)-oxido-l7a-hydroxy-l,4-pregnadiene-3,20-dione, which is recoverablefrom the reaction mixture by chromatography and can be further purifiedby recrystallization from Skellysolve B hexanesacetone. Reaction of thesaid 9(ll)-oxido compound in methylene chloride solution with aqueoushydrogen fluoride or hydrogen fluoride gas in the presence oftetrahydrofuran at room temperature is productive of 6,90;-difiuoro-11B,17x-dihydroxy-1,4-pregnadiene 3,20 dione. Substitution ofaqueous hydrogen chloride for the hydrogen fiuoride above yields6-flllO10-9oc-Cl'll0IO-l113,17a-dihydroxy-l,4-pregnadiene-3,20-dione. Ifdesired, either the 9ot-fluoro or chloro product can be oxidized, forexample, with N-bromoacetamide in pyridine solution to give6,9a-difluoro-17a-hydroxy-1,4-pregnadiene-3 ,11,20- trione or thecorresponding 9a-chloro compound.

The steps of the foregoing process for the preparation of the 9ot-halosteroids can be inverted without departing from the basic concepts ofthe process. Thus, 6- fluoro 113,170: dihydroxy 21 acyloxy 1,4pregnadiene-3,20-dione, rather than a 21-desoxy steroid, may be employedas the starting material and 9a-halogenation --tl '1en at roomtemperature for 72 hours. .was then washed with a five percent aqueoussolution accomplished as indicated above; prior to deoxygenation at the2l-position. The 21-acy1oxy steroid can be prepared'iri the mannercustomarily employed for acylating hydrocortisone, for example, byreaction of the appropriate 21-hydroxy steroid with the anhydride oracid halide of an organic carboxylic acid containing from one of twelvecarbon atoms, inclusive, under conventional esterifying conditions. Inthis variation of the process the 6-fluoro-21-acyloxy steroid can bedehydrated with N-bromoacetamide and anhydrous sulfur dioxide as beforeto produce 6-fluoro-l7a-hydroxy-21-acyloxy-l,4,9(11)-pregnatriene3,20-dione, which can then be reacted withN-bromoacetamide or N-iodosuccinimide in an acidic aqueous organicsolution to yield 6-ll11OIO-9ocbromo-l15,17a-dihydroxy-1,4-pregnadiene-3,20-dione or the corresponding6-flI1OIO-9oc-i0d0 compound. The said 9a-bromo or 9a-l0d0 steroid can bereacted with anhydrous potassium acetate to give6-flllOIO-9(l1)-OXidO-17ahydroxy-Zl-acyloxy-1,4-pregnadiene-3,20-dione.Reaction of the 9(ll)-oxido steroid with hydrogen fluoride or hydrogenchloride yields 6,9a-difluoro-11fl,l7a-dihydroxy-2l-acyloxy-1,4-preguadiene-3,20-dione or its 9u-chloro analogue, andhydrolysis, as with potassium bicarbonate, gives the corresponding21-hydroxy compounds. Either hydrolyzed product can then be oxidized tothe ll-keto steroid or subjected to the reaction described herein forobtaining the 21-desoxy steroid, i. e., converting the said6,9a-difiuoro-21-hydroxy steroid to the corresponding 21- alkyl orarylsulfonate by reaction with an organic sulfonyl halide, obtainingtherefrom the corresponding 21- iodo steroid by reaction of the said2l-alkyl or arylsulfonate with an alkali-metal iodide, and finallyproducing 6,9a-difluoro- 1 1p,17u-dihydroxy-1,4-pregnadiene-3,20- dioneby dehalogenating the said 21-iodo steroid with a reducing agent. Ifdesired, the 6,9u-difiuoro-21-desoxy steroid can be oxidized by reactionwith chromium trioxide in acetic acid or with a haloamide or haloimideas described previously to give 6,9a-dlflllOIO-l7a-hYdIOXY-1,4-pregnadiene-3,1 1,20-trione.

In the foregoing processes, it should be understood that thecorresponding 6fi-halo epimer can be utilized at any stage and the6a-epimer obtained at appropriate intermediate stages by treatment ofthe 6 3-compound, at temperatures of zero degrees centigrade or slightlylower and in an organic solvent such as chloroform, with an anhydrousmineral acid, such as hydrochloric acid, in the presence of alcohol.Such temperatures should be maintained throughout the period of additionof the acid. The reaction mixture can then be washed with successiveportions of dilute alkali and water and evaporated under reducedpressure.

The foregoing reactions are exemplified in greater detail below. It willbe understood by those skilled in the art, nevertheless, that thespecific order of steps may be inverted or transposed or otherwisevaried to suit the purposes of economics, convenience or the like.

The following preparations and examples are illustrative of the processand products of the present invention but are not to be construed aslimiting.

PREPARATION 1 3-ethylene glycol ketal of methyl 3,11-diket0-5a,6a-0xid0-1 7( [cis] -pregnen-21 -oate To a solution of five grams of the3-ethylene glycol ketal of methyl3,1l-diketoe4,l7(20)-[cis]-pregnadien-21- oate, prepared in the mannerdescribedin U. S. Patent 2,707,184; in 100 milliliters of chloroform wasadded a chilled solution of 1.9 grams of perbenzoic acid dissolved in31.5 milliliters of chloroform. The solution was maintained at aboutfour degrees centigrade for 24 hours, and The solution of sodiumbiscarbonate and then with water. The chloroform layer was separated,dried and the solvent distilled milliliters of benzene.

to give a residue of=5.3 grams of-.solid. Crystallization of this solidfrom methanol gave.2.24 grams of product melting at to degreescentigrade andafter two crystallizations from methanol, there wasotbained pure 3-ethylene glycol ketal of methyl 3,l1-diketo5a,6o-oxido-17(20)-leis]-pregnen-21-oate, melting at 206 and 209 degrees centigrade,having an [111 of 37 degrees (CHCl and the analysis given below:

Analysis..-Calculated for C H O C, 69.20; H, 7.75. Found: C, 69.59; H,7.81.

PREPARATION 2 Methyl 3,1 1 -diketo-5a,6e-dihydroxy-1 7 (20 -allopregnen-21 -0ate and methyl .i,11-a iketo-5ot-hydrovcy-6l5-fluoro 1 7(20)-all0pregnen-21-0ate To a solution of 1.73 grams of 3-ethylene glycolketal of methyl 3,1 1-diketo-5a,6a-oxido- 17(20) -[cis] -pregn en-21-oate in sixteen milliliters of methylene chloride was added sixmilliliters of 48 percent hydrofluoric acid. The

heterogeneous mixture was stirred for two hours, made slightly basicwith 300 milliliters of five percent sodium bicarbonate solution, andextracted with methylene chloride. dryness to give 1.62 grams of crudesolid. Chromatography gave two fractions: A, 481 milligrams eluted withmethylene chloride plus five percent acetone and B, 921 milligramseluted with methylene chloride plus ten and twenty percent acetone.Crystallization of fraction A from acetone-Skellysolve B hexanes gave390 milligrams of methyl 3,1 l'-dlkEtO-Sd-hYClI'OXY-6fi-flll0lO-17(20)-a1lO- prcgnen-Zl-oate, melting point 254 to 260 degreescentigrade. The analytical sample melted at 260 to-263 degreescentigrade.

Analysis.Calculated for C H O F: F, 4.84. Found: F, 4.47.

Fraction B on crystallization from acetone-Skellysolve B hexanes gave470 milligrams of methyl 3,11-diketo- 5a,6;8 dihydroxy 17(20)allopregnen 21 oate, melting point 235 to 245 degrees centigrade. Theanalytical sample melted at 245 to 248 degrees centigrade.

Analysis.Calculated for C H O C, 67.67; H, 7.74. Found: C, 67.91; H,7.62.

PREPARATION 3 A mixture of 1.9 grams of methyl 3,l1-diketo-5a-hydroxy 6pfluoro 17(20) allopregnen 21 oate, 59 milligrams of p-toluenesulfonicacid monohydrate and 31 milliliters of distilled ethylene glycol wasadded to 800 The mixture was stirred and refluxed for two hours, withthe condensate passing through a water trap to remove the water. Afterreflux the mixture was. cooled, washed with water and evaporated todryness to give a crude solid which on recrystallization fromacetone-Skellysolve B hexanes gave 1.96 grams of methyl 3,11 diketo 5ahydroxy 65 fluoro 17(20)- allopregnen 21 oate 3 ethylene ketal, meltingpoint 170 to 173 degrees centigrade.

1 Following the above procedure, substituting other dihydric alcoholsfor ethylene glycol, for example, 1,2- propylene glycol, 2,3-butanediol,1,3-butanediol and 2,3- pentanediol is productive of the respective3-alkylene keallopregnen-Zl-oate.

PREPARATION 4 504,115,21 trihydroxy 66 fluoro 17(20) allopregnen-3-0ne3-ethylene ketal To a solution of 1.96 grams of methyl3,11-dik6t0-50zhydroxy 65 fluoro 17(20) allopregnen 21 oate The extractwas washed, dried, and evaporated to liters of water was added slowlyand the ether phase separated. The aqueous phase was extracted withethyl acetate and the extracts added to the ether phase. The combinedether-ethyl acetate solution was washed with water, dried and evaporatedto dryness under reduced pressure. The crude solid residue wascrystallized from acetone-Skellysolve B hexanes to give 1.30 grams of504,115,21 trihydroxy 6,8 fiuoro 17(20) allopregnen-3-one 3-ethyleneketal, melting point 197 to 205 degrees centigrade. An additional 226milligrams was obtained from the mother liquor, melting point 175 to 185degrees centigrade.

PREPARATION 5 50;,115 dihydroxy 6B fluoro 21 acet xy I7(20)-allpregnen-3-0ne 3-ethylene ketal The acetate was prepared by allowing0.87 gram of a,1l/3,Z1 trihydroxy 6 3 fiuoro 17(20) allopregnen-3-one3-ethylene ketal to stand overnight in ten milliliters of aceticanhydride and ten milliliters of pyridine. The solution was then pouredinto ice water to give 0.92 gram of 5a.,11B dihydroxy 6(3 fluoro 21acetoxy- 17(20)-allopregnen-3-one 3-ethylene ketal, melting point to 140to 150 degrees centigrade, which on recrystallization fromacetone-Skellysolve B hexanes gave 0.77 gram, melting point 149 to 153degrees centigrade.

Similarly, other 21-organic carboxylic esters of 504,115, 21 trihydroxy6/3 fiuoro 17(20) allopregnen 3- one 3-ethylene ketals are preparedwherein the 21-acyloxy group is formyloxy, propionyloxy, butyryloxy,valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, benzoyloxy,phenylacetoxy, or the like, by contacting 501,115,21- trihydroxy 6pfluoro 17(20) allo-pregnen 3 one 3-ethylene ketal with an appropriateacylating agent, e. g., I

the anhydride or acid halide of the selected acid in a solvent such as,for example, benzene, toluene, pyridine or the like.

. PREPARATION 6 50L,11fi,17u. trihydroxy 65 fluoro 21 ace!0xyall0pregnane-3,20-dione 3-ethylene ketal To a solution of 0.77 gram of50,l1B-(lihYdlOXY-6B- fluoro 21 acetoxy 17 (20) allopregnen 3 one 3-ethylene ketal in 35 milliliters of tertiary butyl alcohol was added onemilliliter of pyridine, 1.9 milliliters of N- methylmorpholine oxideperoxide solution, and 13.1 milligrams of osmium tetroxide (9.1milliliters of tertiary butyl alcohol solution containing 1.44milligrams 050 per milliliter). The solution was stirred for a period of2.5 hours, fifteen milliliters of five percent sodium hydrosulfiteadded, stirred for an additional ten minutes, 0.7

gram of finely ground synthetic magnesium silicate added, stirred for aperiod of twenty minutes more and filtered. The filtrate was taken todryness under reduced pressure (below fifty degrees centigrade) and theresidue dissolved in methylene chloride, washed with water, dried andevaporated to dryness. This residue was crystallized fromacetone-Skellysolve B hexanes to give 0.47 gram of 5a,11}3,17o4trihydroxy 613 fluoro 21 acetoxyallopregnane-3,20-dione 3-ethyleneketal, melting point'220 to 228 degrees centigrade.

PREPARATION 7 5a,11,8,170t trihydroxy 6ft fizmfo 21-acetoxyallopregnane-3,20-di0ne- A solution of 0.47 gram of5a,115,17u-trihydroxy-6B- .fluoro 21 acetoxyallopregnane 3,20 dione 3ethylene ketal in 35 milliliters of acetone and four milliliters of 1Nsulfuric acid solution was gently boiled on the steam bath for tenminutes, cooled and neutralized with dilute sodium bicarbonate solution.Addition of water and cooling gave 0.33 gram of 511,11B,17z-trihydroxy-6;3- fluoro 21 acetoxyallopregnane 3,20 dione, meltingpoint 230 to 240 degrees centigrade.

r 8 PREPARATION s 63- fluora 115,170: dihydroxy 21 acetoxy 4pregnene-3,20-dione (6B-flu0r0hydr0c0rtis0ne acetate) A solution ofmilligrams of 5 a,115,17a-trihydroxy,- 6/5 fiuoro 21 acetoxyallopregnane3,20 dione in 4.9 milliliters of acetic acid and 0.1 milliliter of waterwas refluxed for a period of one hour, cooled, diluted with fiftymilliliters of water and evaporated to dryness under reduced pressure.The residue was chromatographed over Florisil (synthetic magnesiumsilicate) to give one fraction (77 milligrams) eluted with methylenechloride plus ten percent acetone. Crystallization fromacetone-Skellysolve B hexanes gaves 38 milligrams of 6 8 fluoro 11/3170;dihydroxy 21 acetoxy 4 pregnene-3,20-dione (GB-fluorohydrocortisoneacetate), melting point 210 to 218 degrees centigrade. Infrared data andultraviolet data are in agreement with the structure.

PREPARATION 9 6 a-fluoro-I 1 8,1 7or-dihydr0xy-21-acet0xy-4-pregnenc-3,20-di0nc (6 a-fluorohydrocortisone acetate) A solution of 0.132 gramof 6/8-fiuoro-1lfi,17a-dihydroxy-21-acetoxy-4-pregnene-3,20-dione intwelve milliliters of chloroform and 0.1 milliliter of absolute alcoholwas cooled to minus ten degrees centigrade in an ice-salt bath. A streamof anhydrous hydrochloric acid was gently bubbled through the solutionfor two and one-half hours, during which period the temperature wasmaintained between minus five and minus fifteen degrees centigrade. Thesolution was then diluted with 25 milliliters of chloroform, washed withdilute aqueous sodium bicarbonate solution, dried over anhydrous sodiumsulfate, and evaporated to dryness under reduced pressure at sixtydegrees centigrade. Crystallization of the residue fromacetone-Skellysolve B hexanes solution gave 42 milligrams of theisomerized product, 6a-fi110r0-11fi,l7adihydroxy-21-acetoxy-4-pregnene-3,20-dione, which melted at 203 to 210degrees centigrade.

PREPARATION l0 6 u-fl uoro-I 15,] 711,21 -trih ydr0xy-4 -pregn cue-3,ZO-d i one (6 a-fluorohydrocortisone) and the 6/:t-epimer thereof Asolution of 1.1 grams of 6a-fluoro-11fi,17a-dihydroxy-2l-acetoxy-4-pregnene-3,20-dione, one gram of potassium bicarbonate, 100milliliters of methanol and fifteen milliliters of water were mixedtogether and purged with nitrogen to remove dissolved oxygen whilestirring at 25 degrees centigrade for four hours. The solution was thenneutralized by addition of acetic acid and distilled under vacuum toremove the methanol. The residue was extracted with 100 milliliters ofmethylene dichloride and the extract dried over sodium sulfate andpassed through a column containing eighty grams of Florisil (syntheticmagnesium silicate). The fraction eluted with Skellysolve B hexanes plustwenty and thirty percent acetone weighed 770 milligrams, representing ayield of 77.5 percent. Recrystallization of a portion of this crudeproduct from ethyl acetate-Skellysolve B hexanes gave crystals meltingat 192 to 195 degrees centigrade.

Substituting Gfl-fluorohydrocortisone acetate, from Preparation 8, inthe foregoing procedure is productive of 6/3-fiuorohydrocortisone.

PREPARATION 1 l To a solution of 0.5 gram of 6fl-fluoro-llB,17a,2l-trihydroxy-4-pregnene-3,20-dione and one milliliter ofpyridine in 35 milliliters of tertiary butyl alcohol was added 250milligrams of N-bromoacetamide. After maintaining at room temperaturefor sixteen hours, the reaction mixture was diluted with 25 millilitersof water containing250 'milligramsof sodium sulfite and concentrated toabout twenty milliliters, at which point precipitation occurred. Thethus obtained precipitate was collected on a filter and recrystallizedthree times from ethyl acetate and Skellysolve B hexanes to give6}3-fluoro-17a.,21- dihydroxy-4-pregnene-3, l 1,20-trione.

- Substitution of the corresponding 6a-epimer for the starting materialabove is productive of '6a-fluoro-17a,21-dihydroxy-4-pregnene-3,l1,20-trione. Alternatively, the 6a-epimer can beobtained from the corresponding 65- product by the procedure ofPreparation 9.-

PREPARATION 12 one (A -6a-flu0r0hydr0c0rtis0ne or 611-uoro-I-dehydrohydrocortisone) (I) Five 100-milliliter portions of amedium, in 250-milliliter Erlenmeyer flasks, containing one percentglucose, two percent corn steep liquor (sixty percent solids) and tapwater, were adjusted to a pH of 4.9. This medium was sterilized for 45minutes at fifteen pounds per square inchpressure and inoculated with aone to two day growth of Sepzomyxa afiinis, A. T. C. C. 6737. TheErlenmeyer flask was shaken at room temperature (about 26 to28 degreescentigrade) for a period of three days. At the end of this period this500-milliliter volume was used as an inoculum for ten litersof the sameglucosecorn steep liquor medium which in addition contained tenmilliliters of an antifoam compound (a mixture of lardoil andoctadecanol). The fermenter was placed in the water-bath, adjusted to 28degrees centigrade and the contents stirred (300 R. P. M.) and aerated(0.3 liter air to five liters of beer). After 24 hours of incubation,when a good growth had been developed, five grams of6a-fluorohydrocortisone acetate plus one-half gram of 3-ketobisnor-4-cholen-22-al, dissolved in 25 milliliters of dimethylformamide, was added and the incubation carried out at the sametemperature (28 degrees centigrade) and aerated for a period of 72 hours(final pH 8.3). The mycelium was filtered off and washed with water. Thewash water was combined with the filtrate and the whole was extractedwith three two-liter portions of a mixture of methylene-ethyl acetate(3:1). Removal of the'solvent by evaporation gave 5.25 grams ofcrudesolid which was triturated twice with four milliliters of methylenechloride to give 2.4 grams of 6a-fluoro-1-dehydrohydrocortisone ofmelting point 198 to 203 degrees centigrade. The analytical sample,recrystallized from acetone, melted at 202 to 204 degrees centigrade.Analy sis gave [al plus 73 degrees (dioxane) and the following: 3

Analysis.-Calcd. for C21II2705F: C, 66.65; H, 7.10; F, 5.02. Found: C,66.68; H, 7.19; F, 5.49.

Substitution of the 6B-epimer for the starting material above isproductive of 1-dehydro-6/3-fluorohydrocortisone. The Gp-epimer can beconverted to the Ga-epimer followingthe procedure of Preparation 9.

EXAMPLE 1 6 a-fluoro-l 113,1 7a-dihydr0xy-1,4-pregnadiene- 3,20-dione(IV) 300 milligrams of 6e-fluoro-l1/8,l7a,21-trihydroxy-l,4-pregnadiene-3,20-dione was dissolved in three milliliters of pyridineand cooled from zero to five degrees centigrade. One-tenth of onemilliliter of methane-sulfonyl chloride was added and the solutionmaintained at zero to five degrees centigrade. When poured into asolution of three milliliters of concentrated hydrochloric acid in fiftymilliliters of water, crystalline 6a-fit101O1l;3,17a,21trihydroxy-l,4-pregnadiene-3,20dione 21-methanesulfonate precipitated.The yield of product was 310 milligrams and melted at 200 to 202 degreescentigrade with decomposition. Infrared absorption in amineral oil mullwas as follows: 3570, 3370 cehtimetrs-l-(OH); 1727 centimeters- (20ketone); 1665 centimeters- (conjugated ketone); 1623, 1601 centirneters-(A 1360, 1342, 1172 centimeters" (080 t A mixture of milligrams of6ot-fluoro-llfi,l7a,2ltrihydroxy 1,4 pregnadiene 3,20 dione21-methanesulfouate and 100 milligrams of sodium iodide in fivemilliliters of acetone was refluxed for fifteen minutes. The solvent wasremoved by vacuum distillation. The crude 6a fluoro 21 iod'o 1113,1704dihydroxy-1,4- pregnadiene-3,20 dione (III) was not isolated butdissolved in two milliliters of acetic acid. After fifteen minutesenough aqueous sodium thiosulfate was added to discharge the iodinecolor. The reaction solution was poured into dilute potassium carbonatesolution. The crude product was filtered. It weighed 65 milligrams.Several recrystallizations from ethyl acetate yielded seventeenmilligrams of Ga-tluoro-l15,17a-dihydroxy-L4- pregnadiene-3,20-dionewith a melting point of 271 to 274 degrees centigrade. The infraredmaximums in mineral oil mull are as follows: 3390 centimeter? (OH); 1705centimeters" (ketone); 1652 centimeters" (conjugated ketone); 1613, 1597centimeters- (A Analysis.-Calcd. for C l-1 1 0 C, 69.59; H, 7.51; F,5.24. Found: C, 70.07; H, 7.71; F, 4.29.

EXAMPLE 3. 6B-epimers Instead of the l-dehydro-6ot-fluorohydrocortisoneor l-dehydro-6tx fiuorocortisone, the 6/3-flu'oro epimers can be used asstarting material, in which case the 6B-fiuoro- 116,170: dihydr-oxy 1,4pregnadiene 3,20 dione and 6p-fiuoro 17a hydroxy 1,4pregnadiene-3,11,20- trione, can be isolated from the reaction mixture.The thuseobtained B-epimers yield the 6a-epimers by treatment with acidor base in an organic solvent, e. g., ethanol at room temperature.

7 EXAMPLE 4 i I 6a-flu0r0-I7u-hydroxy-l,4-pregnadiene-3J1,ZO-trioneTreating 1 dehydro-6u-fluorocortisone with methanesulfonyl chloride in"pyridine solution yielded 6DL-flll0i0- l7a,21 dihydroxy 1,4 pregnadiene3,11,20 trione 2l-methanes-ulfonatc; refluxing the thus-obtained6afiuoro .l7o't,2l dihydroxy 1,4 pregnadiene- 3,11,20- trioneZl-methanesulfonate with potassium iodide in acetone yielded 6ac-flu01'017a. hydroxy 21 iodo-l,4- pregnadiene-3,11,20-trione, and reducing withsodium thiosulfate the 6oz-flu0f0 17a hydroxy 21 iodo-l,4-pregnadiene-3,11,20-trione yielded 6a-fluoro-l7ahydroxy-1,4-pregnadiene-3, l 1,20-trione.

A mixture of one gram of 6zx-fluoro-llp,l7u-dihydroxyl,4-preguadiene-3,20-dione, 650 milligrams ofN-bromoacetamide and six milliliters of pyridine were stirred in thedark for a period of thirty minutes. The mixture was .iCOOlGd in anice-water bath and a stream of sulfur dioxide was directed onto thesurface of the stirred mixture until a negative potassium iodide starchtest was obtained. Fifty milliliters of Water was then added to themixture and the mixture was maintained at about five degrees ccntigra-defor thirty minutes. The precipitated White solid wasfiltered, washedwith water and dried under vacuum. After crystallization from acetonethere was obtained about 0.75 gram of 6w-fluoro-17a-hydroxy-1,4,9(11)-pregnatriene-3,ZO-dione.

0.5 gram of 6e-fiuoro-l7ot-hydroxy-1,4,9(l1)-prcgnatriene-3,20-dione wasdissolved in :twenty milliliters of methylene chloride and thereto wasadded a solution of one milliliter of 71 percent perchloric acid in tenmilliliters of water and 200 milligrams of N-bromoacetamide in fiftymilliliters of tertiary butyl alcohol. The solution was maintained atroom temperature for fifteen minutes and then mixed with a solution of0.3 gram of sodium sulfite in twelve milliliters of water. The mixturewas distilled at reduced pressure until the residual solution becamecloudy. The product was then precipitated by the addition of 100milliliters of a mixture of ice water. The White crystalline precipitatewas filtered, washed with water and then dried and recrystallized from amixture of acetone and Skellysolvc B hexane hydrocarbons to give6a-lluoro-9a-bromo-11p,l7 xdihydroxy 1,4-pregnadiene-3 ,20- dione.

A mixture of 0.45 grain of 60: -l'luoro 90c bromol1;8,l7a-dihydroxy 1,4pregnadiene 3,20 dione, 0.45 gram of anhydrous potassium acetate andtwenty milliliters of acetone was heated at its refluxing temperature;for five hours. The mixture was then cooled and poured into water andextracted with methylene chloride. The methylene chloride extract wasdried and poured over a column of 25 grams of Florisil syntheticmagnesium sili cate. The column was developed with Skellysolve B hexanehydrocarbons containing increasing portions of acetone. The SkellysolveB plus ten percent acetone cluate contained9(11)-oxido-l7ot-hydroxy-6ot-fluoro-1,4- pregnadiene-3,20-dione.

A solution of one gram of 9(1l)-oxido-17ot-hydr0xy- 6ot-fiuoro 1,4pregnadiene 3,20 dione was dissolved in fifty milliliters of methylenechloride and thereto was added five milliliters of 48 percenthydrofluoric acid and 0.5 milliliter of 71 percent perchloric acid. Themixture was stirred vigorously for six hours and then poured into anexcess of cold aqueous five percent sodium bicarbonate solution. Themethylene chloride layer was separated, dried with. anhydrous sodiumsulfate, and then poured over a column of 100 grams of Florisilsynthetic magnesium silicate. The column was developed with SkellysolveB hexanes and acetone. the fractions containing ten percent acetone wererecrystallized from acetone and Skellysolve B hexanes to give pure60,9otdifiuoro-l 118,Wot-dihydroxy-1,4-pregnadiene-3,20-dione.

EXAMPLE 6 6059:! difluoro 17a hydroxy 1,4 pregnadiene 3,11

ZO-trione A mixture was prepared containing 0.3 gram of 60:,9adifiuoro11;.8,17a dihydroxy 1,4 pregnadiene 3,20-

dione, milligrams of chromic anhydride, ten milliliters of glacialacetic acid and 0.5 milliliter of water. This mixture was stirred andmaintained at room temperature for eight hours. The mixture was pouredinto fifty milliliters of ice water and neutralized with dilute sodiumhydroxide. A precipitate was formed and was collected on a filter. Theprecipitate was recrystallized three times from a mixture of ethylacetate and Skellysolve B. The purified product was6e,9a-difluoro-l7ehydroxy-1,4-pragnadiene-3,11,20-trione.

It is to be understood that the invention is not to be limited to theexact details of operation or exact compounds shown and described, asobvious modifications and equivalents will be apparent to one skilled inthe art, and the invention is therefore to be limited only by the scopeof the appended claims.

We claim:

1. A compound selected from the group consisting of 6 fluoro 115,170;dihdroxy 1,4 pregnadiene 3,20- dione and6-fiuoro-Hts-hydroxy-l,4-pregnadiene-3,l1,20- trione.

2. 6 fluoro 11B,l7cc dihydroxy 1,4 prcgnadiene 3,20-dione.

3. 6a fluoro 115,170; dihydroxy 1,4 pragnadiene- 3,20-dione.

4. 6 fluoro 17a hydroxy 1,4 pregnadiene-3,11,20- trione.

5. 6a fluoro 17a hydroxy 1,4 pragnadiene 3, l 1,20-trione.

6. A compound of the formula:

CHiOSOzR References Cited in the file of this patent UNITED STATESPATENTS 2,783,226 Gould et a1. Feb. 26, 1957 2,816,121 Gould et a1 Dec.10, 1957 2,816,902 Gould et al. Dec. '17, 1957 2,819,264 Gould et a1.Jan. 7, 1958

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 6 - FLUORO -11B,17A - DIHYDROXY - 1,4 - PREGNADIENE - 3,20DIONE AND6-FLUORO-17A-HYDROXY-1,4-PREGNADIENE-3,11,20TRIONE.